A method for coating a printing screen with a sealer to avoid pinholing and damage to the screen from extended use. The method includes coating the inside of the screen with a photo emulsion, exposing the emulsion to the image to be printed, and etching out the exposed screen. Next, applying to the outside surface of the etched out screen a sheet of easy removable pressure sensitive vinyl, and next treating the etched out screen with a sealing composition, which provides a protective barrier for...

The present power pack for a portable cellular telephone has a concealed radio transmitter for law enforcement use. The usual battery compartment in the housing of the power pack has a shortened battery compartment above which are located interior walls of the housing which are notched or recessed to support a printed circuit board carrying a radio transmitter. The housing has a shallow recess on the inside in which an antenna is potted. A space inside the housing receives a microphone for the r...

A superimposing image apparatus for superimposing a first view on a second view, including an optical imaging system which has a given focal length, an image plane and given field of view which encompasses the second view, and an arrangement for translationally moving a first mirror within the aforesaid field of view and positioned so as to project at least a part of the first view into the lens system, superimposed on the second view. In accordance with a second feature, there is provided a sup...

This model rocket car carries a U-shaped tube with lower and upper straight segments connected at their front ends by a bight segment. The lower segment of the tube holds a model rocket engine which, upon ignition, first ejects gas out the back end to propel the car forward and after a burning time ejects gas from its front end forward into the tube. The upper segment of the tube holds a folded braking parachute, tethered to the car, which is blown out of the tube by the gas ejected from the fro...

A traffic light control system which includes two-way communications between a moving emergency vehicle approaching a busy intersection with one or more traffic lights, arranged so that the traffic light control apparatus has stored therein preset patterns of response that temporarily preempt the usual operation of the traffic light and instead provides the most effective method of routing the vehicle through the intersection while redirecting general traffic. As part of the invention, the traff...

A pin fraud and shock prevention circuit for a pay telephone which has a receiver and transmitter, a tip and ring conductor forming a current loop connecting the pay telephone to a telephone exchange, and which has a current sensor in the ring conductor, a plurality of current switches coupled to the current sensor for connecting the receiver and transmitter to the loop in response to current flowing in the loop.

An extensible and retractable step assembly for a floor cabinet having an open rectangular base slidably mounted in an interior space at the bottom of the cabinet immediately above the floor and selectively positionable in the cabinet or in front of the cabinet, a step which fits inside this base, and slidable pivoted linkages connecting the step to the base and permitting the step to be raised up from the base when the base is extended in front of the cabinet.

Method and apparatus for injection molding an elstomeric fishing lure body for a weedless lure between cooperating dies which together define a mold cavity. One of the dies has a long, deep, narrow rib projecting into the mold cavity to form a complementary recess in the fishing lure body for concealing the hook end of a fishhook. A reciprocable plunger extends into the mold cavity at one end to form an anchoring recess for a metal or plastic head that is to be attached to this end of the elasto...

A golfer's elbow stiffener comprising fabric material having a series of pockets containing stiffening strips and a cover detachably fastened over the pockets and stiffening strips. The fabric material and the stiffening strips are adapted to encircle a golfer's elbow for bracing the elbow on all sides to keep it straight when swinging. The stiffening strips are easily removed from the pockets upon detaching the cover so that the fabric material may be cleaned.

The present fastener for holding a stack of loose leaf pages has a base piece with easily flexible and resilient plastic prongs and a top piece with openings for passing the prongs and sliders for holding the prongs folded down on the top piece. The prongs are constructed and arranged to flex readily when released from beneath the sliders in the top piece and pages in the top of the stack are folded out. The prongs have shoulders near their outer ends for preventing the complete removal of the t...